World War II Projectile Saipan

The business end of a World War II projectile uncovered in a vacant field after some heavy rains in Saipan. Grateful if someone could help with an ID. I'd say it was at least 6 inches in length. We didn't touch it. Note the broken shard of Chamorro pottery inthe background. It is likely over 500 years old.

For photos, videos and great info on Saipan and it's history, particularly World War II, please take a look at SaipanPictures' blog, at saipanpictures.blogspot.com/